The formula H2O is also the molecular formula of water. For non-molecular substances such as table salt, we represent the composition with an empirical formula. Sodium chloride is represented by NaCl, meaning that sodium and chlorine ratio in sodium chloride is 1 to 1. Again, the subscript 1 is omitted.
By Phil Myers. The annelids include earthworms, polychaete worms, and leeches. All members of the group are to some extent segmented, in other words, made up of segments that are formed by subdivisions that partially transect the body cavity.Segmentation is also called metamerism.y Phil Myers. The annelids include earthworms, polychaete worms, and leeches. All members of the group are to some extent segmented, in other words, made up of segments that are formed by subdivisions that partially transect the body cavity.
Worms are in a very broad category that is not officially classified in any scientific sense. While most worms are limbless invertebrates, some worms are actually reptiles or amphibians. Many other animals called worms are simply insect larvae that have yet to metamorphose into their adult stage.